Basic Analog Circuits using Ideal Op-amps:

In the following, we illustrates different controlled sources and other useful circuits, which may be realized by using IC op-amps.

VCVS Circuits

Assume the 3-port VCVS of Figure. Supposing ideal op-amp (i.e. Z_in = ∞, Z₀ = 0, A → ∞) the node equation at node m is

V₂  - V_m /R₁ = V_m  - V₀ /R₂

Figure: The 3-port VCVS

Solving for Vm gives,

V_m   =  (R₂/ R₁ + R₂ )V  + (R₁/ R₁ + R₂)V₀

Also,

 (V₁ - V_m ) A = V₀

or (V₁  - V _m ) = V ₀ /A

which means V₁ = V_m as A → ∞

From (50) and (52), we determine

V₀  =  (1 +( R₂ / R₁) )V₁  - (R₂ / R₁)V₂